Here's the information that we have from our "research"... My degree info has some error as my degree wheel may not have been accurately centered as the hole in the wheel is larger than the bolt and I did my best to eyeball it... I now have a bushing to center it more accurately for future checks...
68 340 4 speed cam from service manual:
Intake op: 26° BTC
Intake cl: 70° ABC
Exhaust op: 78° BBC
Exhaust cl: 26° ATC
Overlap: 52°
Intake duration: 276°
Exhaust duration: 284°
Intake lift: .444"
Exhaust lift: .453"
Calculated from valve open/close specs:
Intake duration: 276°
Exhaust duration: 284°
Intake Cl: 112° ATC
Exhaust Cl: 116° BTC
Lobe Center: 114°
68 340 Auto cam from service manual:
Intake op: 22° BTC
Intake cl: 66° ABC
Exhaust op: 74° BBC
Exhaust cl: 22° ATC
Overlap: 44°
Intake duration: 268°
Exhaust duration: 276°
Intake lift: .429"
Exhaust lift: .444"
Calculated from valve open/close specs:
Intake duration: 268°
Exhaust duration: 276°
Intake Cl: 112° ATC
Exhaust Cl: 116° BTC
Lobe Center: 114°
My custom ground 340 Auto Cam layout from Ken Hoard Oregon Cams:
View attachment 1715410762
My custom ground 340 4 Speed Cam layout from Ken Hoard Oregon Cams:
View attachment 1715410761
Oregon cam data vs my degree check:
View attachment 1715410763
340 4 speed data from Service manual:
View attachment 1715410765